Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
ahmad:23277Wakīʿ > Abū al-ʿUmays > Abū Bakr b. ʿAmr b. ʿUtbah > Ibn Liḥudhayfah from his father

[Machine] The Prophet ﷺ used to pray for a man, and his prayer would extend to his son, and his son's son.  

أحمد:٢٣٢٧٧حَدَّثَنَا وَكِيعٌ حَدَّثَنَا أَبُو الْعُمَيْسِ عَنْ أَبِي بَكْرِ بْنِ عَمْرِو بْنِ عُتْبَةَ عَنِ ابْنٍ لِحُذَيْفَةَ عَنْ أَبِيهِ

أَنَّ النَّبِيَّ ﷺ كَانَ إِذَا دَعَا لِرَجُلٍ أَصَابَتْهُ وَأَصَابَتْ وَلَدَهُ وَوَلَدَ وَلَدِهِ